Rusty Lupine

Annual, Herbs, Taproot present, Nodules present, Stems very short, acaulescent or subacaulescent, Stems erect or ascending, Stems less than 1 m tall, Stems solid, Stems or young twigs sparsely to densely hairy, Stems hairs pilose or spreading, Leaves alternate, Leaves petiolate, Stipules conspicuous, Stipules setiform, subulate or acicular, Stipules persistent, Stipules adnate to petiole, Leaves compound, Leaves palmately 5-11 foliate, Leaf or leaflet margins entire, Leaflets 5-9, Leaves hairy on one or both surfaces, Inflorescences racemes, Inflorescence terminal, Bracts conspicuously present, Bracts very small, absent or caducous, Bracteoles present, Flowers zygomorphic, Calyx 5-lobed, Calyx 2-lipped or 2-lobed, Calyx glabrous, Calyx hairy, P etals separate, Corolla papilionaceous, Petals clawed, Petals blue, lavander to purple, or violet, Petals bicolored or with red, purple or yellow streaks or spots, Banner petal ovoid or obovate, Wing petals narrow, oblanceolate to oblong, Wing tips obtuse or rounded, Keel petals auriculate, spurred, or gibbous, Stamens 9-10, Stamens or anthers dimorphic, alternating large and small, Stamens monadelphous, united below, Filaments glabrous, Style terete, Fruit a legume, Fruit unilocular, Fruit freely dehiscent, Fruit elongate, straight, Fruit oblong or ellipsoidal, Fruit exserted from calyx, Fruit internally septate between the seeds, Fruit compressed between seeds, Fruit hairy, Fruit 2-seeded, Seeds ovoid to rounded in outline, Seed surface smooth, Seeds olive, brown, or black, Seed surface mottled or patchy.

Lupinus pusillus in the Wyoming big sagebrush steppe biome, near Phillips, Montana.

Lupinus pusillus, the rusty lupine or dwarf lupine, is an annual plant in the legume family (fabaceae) found in the Colorado Plateau and Canyonlands region of the southwestern United States(California),: 159  and north to Montana.